RSS stands for Really Simple Syndication.
Syndication means sending out information to more than one outlet. For example, if an article written for the New Your Times goes into “syndication,” that very same article could be seen in other newspapers as well.
Here is a short video explaining the basics of RSS:
So RSS allows content to come to you. How do you view this content? In what is called a “Reader.” One very popular reader is Google Reader.
Here is a short video explaining how Google Reader works: